Hydraulic hammers are one of an assortment of work tools that may be attached to the boom of an excavator, backhoe loader, skid steer or a like machine for breaking large rocks, concrete, etc. In a typical application, the hydraulic hammer is mounted to the machine boom in place of a bucket, and connected to the hydraulic system of the machine. When activated, high pressure hydraulic fluid is supplied to the hydraulic hammer to drive a reciprocating piston into and out of contact with an impact end of a work tool partially received in a powercell housing of the hydraulic hammer. U.S. patent application publication 2008/0296035 shows an example hydraulic hammer for use with an excavator.
Although the internal plumbing of hydraulic hammers from different manufacturers can vary, they often share several features in common. Among these are the use of a switching spool valve that moves between a first position that fluidly connects a downward hydraulic surface of the internal piston to high pressure from the hydraulic inlet, and fluidly exposes the downward hydraulic surface to the low pressure of the hydraulic inlet at a second position. Movement of the switching spool valve is often controlled by a switching volume defined by the piston. As the piston moves, the switching volume connects a control surface of the switching spool valve to either high pressure or low pressure. As a result, each cyclic action of the hydraulic hammer involves one reciprocation of the piston and an associated reciprocation of the switching spool valve.
Although hydraulic hammers have been generally known for many years, they can often be expensive to manufacture. For instance, the hydraulic fluid connections of the hydraulic hammer are often located near the boom mounting features of the hydraulic hammer. In order to plumb fluid connections deep into the powercell housing, fluid passageway drillings with relatively large length to diameter ratios must be made in order to facilitate the assorted fluid connections for the hydraulic hammer. Making these deep drillings is often problematic and extremely expensive.
The present disclosure is directed toward one or more of the problems set forth above.